This article presents production data of sibilant segments by Catalan speakers in a Spanish-Catalan bilingual context. Catalan includes voiced sibilants in its sound system, whereas Spanish only has voiceless ones. Subjects come from two areas of Barcelona differing in the degree of presence of Spanish. Based on previous results on vowel production, we predict that Catalan sibilants, especially the voiceless ones, will be less often produced in a target-like manner in the more Spanish-speaking area, and especially in the younger groups (3&#8211;5 and 19&#8211;23 years old). Our results confirm this prediction for /z/, whereas for the affricate /d&#352;/ percentages of target-like production are low in all groups. These results are accounted for by several internal and external linguistic factors.